The present invention relates to sheets of material preferably wet wipes which are provided with an improved perforation configuration, which is easily visible to the consumer and which allows the wet wipes to be easily separated from oneanother whilst not compromising on strength.
Wet wipes are typically premoistened, disposable towelettes which may be utilised in a variety of applications both domestic and industrial and perform a variety of functions. Wet wipes are typically used to wipe surfaces both animate and inanimate, and may provide numerous benefits such as cleaning, cleansing, disinfecting, and skin care benefits.
One particular application is the use of wet wipes for wiping parts of the human body particularly when wash water is not available, for example when travelling. Wipes are commonly used for human cleansing and wiping such as face and hand cleansing and anal, perineal and genital cleansing for example as intimate hygiene wipes such as feminine wet wipes. Wet wipes may also be used for application of substances to the body including removing and applying of make-up, skin conditioners and medications. Another application of wipes is during diaper changes and also for the treatment of adult and baby dermatitis partly caused by the use of diapers and incontinence devices. In addition wet wipes are also applicable for wiping and or cleaning other surfaces or for the application of compositions to surfaces, for example kitchen and bathroom surfaces, eyeglasses, shoes and surfaces which require cleaning in industry for example surfaces of machinery or automobiles. Wet wipes also include articles used for the cleaning or grooming of pets.
Wet wipes are commonly constructed from combinations of synthetic and natural fibres, such as polyolefin fibres, viscose fibres and cotton fibres, which are generally moistened with an aqueous composition which contains amongst others surfactants, preservatives, oils and scents. The wet wipes are then typically provided in a folded stacked configuration within a covered container such as a tub-like container having a lid. Alternatively, the wipes may be provided in tub containers having a dispensing aperture. In both cases this allows easy transportation and storage of the wipes. Typically the wipes are packaged in a plastic foil in order to protect the wet wipes prior to use.
In order to aid dispensing and to allow the consumer to select the desired size of wipe it is highly desirable to provide the wipes with perforations. The use of perforations is well known in the field of paper, tissue and towels. For example, U.S. Pat. No. 5,704,566 discloses a roll of paper towelling to be dispensed from a dispenser which may be separated into towelling segments by pulling along perforated tear lines. The perforated tear lines comprise a plurality of slits which are longer towards the side edges of the paper than in the middle, to aid dispensing.
Similarly DE 27 06 234 discloses the use of perforated lines of variegated holes formed in a paper sheet, the diameter of which increases towards the edge of the paper so as to facilitate tearing of the paper by one hand.
The use of perforations for wet wipes is particularly advantageous not only in terms of dispensing, but also in allowing the consumer to select the length or amount of wet wipe material required to carry out a particular clearing activity. Thus for small and easy cleaning activities just one wipe can be selected, whilst for larger and dirty cleaning activities a number of wipes can be used. Thus it is not only important that the consumer can easily dispense the size of wipe that is required, it is also equally important that the perforations are strong enough such that they do not break or tear within a larger wipe during the cleaning process. This problem of perforation strength is further exacerbated upon storage of the wet wipes which has been found to generally weaken the perforation.
In addition another important factor with respect to the convenient usage of such wipes, is that the consumer can readily identify the location of the perforations in the wipe substrate. The visibility of the perforations is related to the length of the perforation or slit in the substrate; larger perforations or slits providing easy recognition by the consumer. However a problem with such larger perforations is that the strength of the perforations is further reduced, which is as discussed above highly undesirable. This problem is yet further exacerbated by certain dispensing methods. For example methods which result in continuous dispensing through a container orifice whereby mechanical friction is utilised to dispense and separate the wipes.
It is therefore desirable to provide a wet wipe stacking configuration which is suitable for multiple applications such as baby wipes and hard surface cleaning wipes which are strong, soft, absorbent and provide improved cleaning. It is further desirable to provide wet wipes whereby the wipe substrate is provide with perforated tear lines that are readily visible so that the consumer can select the desired length of wipe required and easily separate the wipes from oneanother, whilst providing sufficient strength so that the perforation within the wipe does not tear or break during use.
The present invention hence relates to a sheet of material, preferably a wet wipe for wiping parts of the human body such as baby wipes and other inanimate surfaces. In particular, the present invention relates to a sheet of material (1) such as a wet wipe, wherein said sheet of material comprises at least one transverse perforation line (20), said transverse perforation line (20), having at least one repeating perforation pattern (21), characterised in that each of said repeating patterns (21) has at least one primary perforation slit (22), at least one secondary perforation slit (23) and at least two bonded areas (24), wherein the length ratio of one of said primary perforation slits (22) to one of said secondary perforation slits (23) is from 100:1 to 1.5:1 and wherein the ratio of the total length of said bonded areas (24), to the total length of said primary (22) and secondary (23) perforation slits of said perforation line is from 1:1 to 1:6.